Up to now, in certain areas of display technology, an electrophoretic electro-optical medium is commonly used, in particular for flexible displays. However, the electrophoretic electro-optical medium is subject to a number of restrictions. The medium has a relatively slow pixel response, which makes video display challenging, and has a relatively low brightness compared to paper.
Displays based on the electrowetting electro-optical medium may remedy at least some of the restrictions mentioned above. A particular variant using this principle is, for example, described in publication WO2004068208. This variant has a height dimension that is relatively large compared to liquid crystal or electrophoretic displays which hinders its use in flexible displays.
The recently developed Electrofluidic Chromatophore (EFC) variant of a display based on electrowetting has a smaller height dimension and may therefore be more suitable to use in flexible displays.
However, when the displayed content does not change, for example during e-reading static images, the EFC display typically needs to be kept in the charged state, in contrast to, for example, E-ink displays that keep their image even without charging the display. Furthermore it is desirable to change the polarity of the charges on the EFC display at regular time intervals to optimize the image quality during the lifetime of the display, which requires discharging and recharging of the display even when displaying static images. This poses a challenge to minimize power consumption—especially when used in battery powered mobile devices.